The present disclosure generally relates to integrated circuits (ICs). In particular, this disclosure relates to the late-stage fabrication of electronic circuit elements used to tune a VCO circuit fabricated as part of the IC.
An IC, also known as a “microchip,” silicon or computer “chip,” is a specially prepared piece of silicon, or other semiconductor material, into which a complex electronic circuit is etched and formed using a photolithographic process. IC types can include computer processors, memory, analog, and customizable devices. ICs can be relatively fragile, and therefore are often mounted on and/or surrounded by a protective, supportive ceramic or plastic package. Electrical connections to the chip can be provided through metal contacts, which can include pins or solder balls located on the exterior of the chip package.
ICs can have certain advantages over comparable discrete circuits, such as relatively low-cost and high-performance. The cost of an IC can be relatively low, resulting from the large number, e.g., millions, of transistors that can be simultaneously printed as a complete functional unit by photolithographic techniques, rather than constructing an equivalent circuit from individually fabricated transistors. Performance of an IC can be significantly higher than an equivalent discrete circuit, due to the high density and relatively low electrical interconnect parasitics between active devices such as transistors. Types of ICs may include analog, digital and “mixed signal” chips, i.e., chips that incorporate both analog and digital functions on the same silicon die.
A capacitor is a passive electrical component having at least two electrical conductors known as plates, separated by a dielectric or insulator, and which may be used to electrostatically store energy in an electric field. Capacitors may be useful as circuit elements in conjunction with a variety of types of electronic devices such as digital and analog ICs.